A number of fiber optic cassettes have been proposed and employed in the communications field. These are typically compact, flat boxes, often of a tough transparent polymer, with a cassette housing portion that receives the network fiber cable, a splice tray on which the network fibers are spliced to connector pigtail fibers or similar fiber harness, with a pre-terminated fan-out of the pigtail fibers to optical connector jacks that are situated on a connector panel at the front of the cassette. Typically, a splice holder is provided in the splice tray to hold the splices in place, and there are members within the cassette for retaining multiple loops of the fibers and cables as pigtail slack and cable slack.
These cassettes are designed to be mounted in a rack or frame or enclosure. Where there are multiple cassettes employed in a given rack or frame, some provision must be made to let the technician pull the cassette out—either by sliding it out or by snapping it out of the rack—for servicing a cable or the individual jumpers that are plugged into the connector jacks.
In all cases, the optical fibers should be kept from bending beyond a predetermined minimum bend radius to avoid reflections and signal loss, as well as to prevent harmful mechanical strains on the fibers.
In prior splice boxes and cassettes, little to no thought was given to the network cable or trunk cable to prevent that cable from bending beyond the minimum radius any time the cassette is slid out or any time it is slid back in.
Also, no steps have been taken to physically protect the fibers and connectors of the jumpers and plug connectors that are plugged into the cassette, or especially to protect the jumpers and connectors of a given cassette when a technician is working on another cassette in the same rack or frame.